Social Network Metrics
Types of network metrics
• Group level
– Density
– Components
• Isolates
– Cliques
– Centralization
• Degree
• Closeness
• Betweenness
– Factions
– Core-periphery
• Node level
– Centrality
• Degree
– Indegree
– Outdegree
• Closeness
• Betweenness
• Visualization
– Netdraw
– Mage
• QAP
• Statistical metrics
– MDS
– Cluster analysis
Preparing the data
• Most graph-based metrics require symmetric,
dichotomous (binary) data
• Symmetrization
– Minimum (captures reciprocal ties)
– Maximum (most inclusive)
• Dichotomize
– Valued data are typically ordinal
– Mean, median or modal values
Network Density
• The proportion of ties that exist out of all
possible ties
• For valued data the sum of all tie strengths
divided by all possible ties
Density is a course measure
Density = .33
Degree centralization = 10%
Density = .33
Degree centralization = 60%
Centrality versus centralization
• Centrality is a node level metric; each node
has a centrality score representing it’s position
within the network
• Centralization is a group level metric
indicating the extent to which the network is
dominated by one or a few nodes